The World's Strongest Engine is the eleventh episode of the sixth season. In Twilight Sparkle Meets Thomas and Friends.
Henry has had an accident pulling a goods train and is sent to the works to be mended, and unfortunately Diesel is the only engine available. The engines are not very happy about this, seeing that they know Diesel is troublesome.
The next day, Diesel is working at the docks and the trucks tease Diesel as he's shunting them, so he boasts he can push them all at the same time. Diesel then arranges a line of twenty trucks, but soon finds he is unable to move them (unbeknownst to him, a shunter has put the brakes on), so Diesel decides to pull them instead. He pulls so hard he breaks loose and falls onto a barge. Henry, who is now repaired, arrives at the docks with The Fat Controller, who is cross with Diesel, and sends him home in disgrace.
Henry then pulls away from the docks, pulling the line of trucks easily. And the engines all agree that even trucks can be helpful sometimes, like helping to get rid of Diesel.
- Trixie guest stars in this episode.
- This episode will lead to the beginning to Thomas' Adventures of My Little Pony Friendship is Magic - Magic Duel.